shadz

for the crackle, make sure you've got a high enough buffer, and your frequency (44.1 kHz for example) matches your soundcard/mic's rated freqeuncy (edit: and operating frequency. I get crackling in some games because I need to be set at 16-bit, 44.1kHz, even without breakaway)
as for the mic, you may need to right click > settings and select your mic as the input every time you connect it. I have to with my headphones, but I think it's to do with how Realtek's software manages the device every time it gets unhooked and hooked in again. The only other thing could be that it's disabled natively in window's sound settings
and that echo might be from accidentally having some form of windows sound effect in the sound settings, or having a reverb enabled in your propriety sound card's software. I know my Realktek's does and I have it disabled

hopefully this is of some help to you both